Need to upgrade or lock rotp at v3.x

[mindtonic]

rotp introduces breaking changes in version 4 [https://github.com/mdp/rotp#breaking-changes-in--40].

[andresantonioriveros]

I found a problem with the otp verification. The verify_with_drift_and_prior call is broken, so I made a branch with a fix as an alternative to lock rotp:
https://github.com/resitcl/two_factor_authentication/commit/d462080c479825da2fcd27acf38c9dddd0a6ae78

I'm using rails 5.2, rotp 4.0.2. It seems to be the only problem that the upgrade introduces.

[kchasel]

Also ran into this issue. We downgraded to 3.3.1 to resolve but applying the above patch to upgradae this library to support rotp >= 4.0 would be great!

[macgill4444]

I also just ran into this issue and would also appreciate an upgrade! :)

[Migoo]

Same here. An update would be graciely appreciated

[andresantonioriveros]

#159

[mindtonic]

Wonderful! Thank you.